Who Has Innocent Syrians’ Blood on Their Hands?

It is now disturbingly apparent that degrading the Islamic State has not created an opening for peace in Syria. Instead, the country’s atrocious president, Bashar al-Assad, and his enablers in Russia and Iran have oppressed the battlefield successes against ISIS to unleash a new round of carnage on civilians, as the leaders of the United States and other world powers hugely stand by, unwilling or unable to do anything to stop it. Shame on them all.

The Assad-led bombardment of eastern Ghouta, a Damascus suburb of about 400,000 people and one of the last rebel-held areas, is being called one of the most violent episodes of the seven-year war. Since Sunday at least 310 people, many of them children, have been killed. That’s in addition to nearly 500,000 Syrians killed countrywide since 2011.

Ghouta has been under siege for years, although it’s technically component of a negotiated de-escalation zone, leaving the district facing chronic shortages of food, medicine, medical personnel and other requirements.

This week’s huge attack — which has involved rocket fire, shelling, airstrikes and helicopter-dropped barrel bombs that struck hospitals and other civilian infrastructure — intensified the misery. It seems intended to force rebels to surrender so the government can reclaim the territory. Most of the civilian casualties resulted from airstrikes on residential areas, the United Nations’ human rights office said. There have been signs that a government ground assault may soon follow.

Images posted on social media are excruciating. Terrified children, faces and bodies covered in blood. Shrouded corpses lined up on dirty concrete floors. Wounded patients on gurneys writhing in agony, lacking medical attention or even drugs to ease their pain. António Guterres, the United Nations secretary general, called Ghouta a “hell on Earth.”

If there was any doubt about the barbarity of the pro-Assad forces, it was dispelled by Brig. Gen. Suheil al-Hassan, leader of the government’s Tiger Force. “I promise, I will teach them a lesson, in combat and in fire,” he said in a video shared by pro-government social media accounts. “You won’t find a rescuer. And if you do, you will be rescued with water like boiling oil. You’ll be rescued with blood.”

That’s the type of evidence that must be utilized — sooner rather than later — to build a legal case to try Mr. Assad for war crimes. The same should be done for Russian leaders, who assist keep Mr. Assad in power with political support and military air assets, and Iranian leaders, who give tactical advice and ground troops. The United Nations human rights chief, Zeid Ra’ad al-Hussein, called what is going on in Ghouta a “monstrous campaign of annihilation” on Wednesday.

The United States and other governments have even accused Mr. Assad of using chemical weapons — banned under international law — in Ghouta and elsewhere in Syria. But world powers have done nothing, beyond an American airstrike last April ordered by President Trump under questionable authority. Russia bears special responsibility because it guaranteed Mr. Assad would give up his chemical weapons as part of a 2013 deal with the United States, which the Syrian leader apparently did not do.

The United Nations Security Council has been particularly impotent at ending the killing between Mr. Assad, a member of a Shiite sect, and the Syrian opposition, made up mostly of Sunnis. Some 11 Syria-related Security Council resolutions have failed to pass because of Russian vetoes.

A new Swedish-Kuwaiti resolution, demanding a 30-day cease-fire in Syria so civilians can be resupplied or flee the war zone, seems destined for the same fate. Russia dismissed the resolution as “not realistic” — a reaction that highlights how protections for civilians in wartime, long a central tenet of international law, are being quickly eroded.

Complicating things even more, the civil war between Mr. Assad and the opposition, once seen as the core of Syria’s instability, is now understood as just one element in a web of conflicts tearing Syria apart. In addition to Russia and Iran, Turkey, the United States and Israel all have a presence in Syria, and their competing interests are raising the specter of wider war, which must be avoided.

What of diplomatic solutions? Russia, after feigning to lead such an effort, lost credibility by siding with Mr. Assad and his route to more carnage. And while the State Department condemned the regime’s violence and named Russia as holding a “unique responsibility” for the suffering, Mr. Trump has effectively abandoned America’s international leadership role in the matter.

This week, as reports of new Syrian casualties rolled in, aid groups and political leaders once again condemned, lamented and called for action. Unicef, the United Nations children’s agency, may have been more honest. Unable to muster more bromides, it issued a statement saying only, “No words will do justice to the children killed, their mothers, their fathers and their loved ones.”